Question

Keith exercises x hours a week. Troy exercises three hours less than Keith and Joe exercises two times more than Troy. Which expression represents the amount of time Joe exercises?

Answer 1

If Keith is represented by x, and Joe is three less than Keith, Troy is represented by x-3. 
Then, we know that Joe exercises for twice the amount of time as Troy, we multiply the expression for Joe by two. 

Keith = x
Troy = x-3
Joe = 2(x-3)